not to rain on the parade more than I have, I really hope it is not a headgasket, but my car ran fine, I could drive 80 miles with no issues, but if I ran the car hard then coolant would spew all over the place and overheat.

So here are myths that didn't prove with mine
- coolant system pressure checked ok
- rad cap was fine
- car ran fine, no misses

and although mine was due to bad sleeve install it would be very similar to a headgasket issue

 

hg fa sho

 

What gus is saying is accurate. As I said this isnt the first time Ive seen a z with the symptoms. You are prolly going to have to pull your motor.

 

+1...everytime I have seen cars with this situation..ie...car runs fine for awhile, then after some hard driving the coolant starts spewing, it's always the gasket. The important thing is determining what caused it FIRST..then fixing it. Was it tuning related, overboost, improper trqing of head studs, poor block or head seating surfaces...etc...etc. All I know, is the open deck engines we assemble and tune here, dont' show these symptoms....even when beating the crap out of at the track. I have given up on sleeves for daily drivers, since the two engines I have seen with head lift, were both sleeved.

 

Head lift and/or HG. Welcome to the club...looks exactly like mine. Purge the air out of the system, take coolant out of the overflow, and go boost it. Mine wouldnt hold full boost, during one 3rd gear pull it would go to 13psi then back down to 10psi,when I let off, the overflow would fill. Good luck!!!

 

This is very strange, because the car had been 3k miles of somewhat aggressive driving (nothing crazy), over 100 passes on the dyno, and ran down the track 7-10 times, then on a very mild at best 2 mile round trip to the dollar general (ironic), is when I have the first problem with the Z.

There were two reasons, I didn't sleeve the engine, the first was I noticed the same thing about the headlift, and second was the financial aspect.

Sharif, I look forward to you helping me out of this mess. I am hoping that it turns out to be a leak in the coolant system, radiator cap, or even a headgasket (even thought I bought the friggin $400 HKS).

 

I definately and obviously am hoping for something minor. Hoping after purging the coolant, she boosts well.

 

Good luck man as i do know everything that Bert went thru with his pre/post problems.

 

Luckily you live in GA.. (FP)

But id hope for an air pocket in the system.. Dont think that would spew coolant though.. Just overheat..
Your cap looks fine, your pics dont show any coolant leaking from the cap..

Btw, looks like you have the stock rad.. Id upgrade if i were u..

 

Classic signs of headlift.

+1 on what Romey, Sharif, and Westpak have stated.

Sorry to hear, what type of temps are you seeing when you track the car?

-George

EDIT: Is this the first reported head lift with L19 studs?

 

It had been heavily wiped down, everywhere.

 

The car never even went halfway up the gauge, never has since day one?

Hoping for good things on the compression and leakdown test.

Craig

 

The stock gauge is too slow/inaccurate.

Did you have a high quality after market gauge?

I have warning set up to go off on my car once it reaches 100 C. I don't feel comfortable at the high of a temp. Just trying to see if the guys who run the car hotter more frequently are lifting their heads more often.

I really hope my 14mm head studs (largest available) prevent any head lift issues, so far we have 3 cars running with them with no issues so far - but only time will tell, seems like every other head stud has had a failure due to one reason or another.

-George

 

Good luck with finding the cause of the issue. If you are using the stock temp gauge you may want to think about an aftermarket version. I have heard oths say that y the time the stock gauge reads hot the damage may already be done.

 

Bro I know you hope for it to be something small. But you will boost and it may not happen right away. But it will happen again.

 

yeah I would get excited when nothing would happen then crushed when it did, denial is a very strong emotion in this instance, I looked for any explanation that would make it all better, it is tough.

 

Adjusted signature accordingly.

 

Alberto and Sharif described it perfectly...

Under your scenario, when you say it's been ok for a while and is only now gone bad, let me attempt to explain how that happens.

Your head gaskets leak VERY slowly, even under full boost, in the beginning stages of failure. This collects air in the system, until at some point a larger bubble coalesces and gets stuck on the thermostat shaft, especially at low rpms. This causes the thermostat to close, leading to the coolant overflow. My point here being, if it's in the starting stages of failure, which it looks like it might be, it will be very difficult or even impossible to diagnose directly with leakdowns/etc.... since the leak is very small and only shows itself under high pressures (thousands of psi) of combustion (without tearing the engine down of course).

What you can do is:

1) if you have a method of clearing out ALL of the air out of the cooling system (that HAS to be done with a special purging system that connects to an air compressor and via a venturi valve creates strong suction/vacuum and also allows you to use that vacuum to refill with coolant afterwords) and go out there and drive the car hard. If you get bubbles bubbling through the overflow, or the reservoir outright overflowing like it did this time, then it's head gasket for certain.

2) if it does not overflow right away, just gives a few bubbles, then there is pretty much 95% chance that it's still the HG, we are just not sure if the purging was 100% complete or not. What's going on here is that the bubbles that did go through the head gasket seal (if the HG is bad) are not large enough to cause a thermostat closure and an outright overheat.

3) If there are NO visible bubbles, then drive the car moderate-to-hard for a few days, and see if you get an overheating/overflow event like you did now. If so, then what I was describing finally happened, there was enough air to cause a thermostat closure (thermostat only opens if actual fluid contacts the metal skin that holds the wax pellet - hot AIR doesn't do it).

Remember, there should be NO reason whatsoever for air to be somehow introduced into the cooling system. Those people that tell you that it's normal to bleed your system every couple of weeks are just pain wrong. If that happens. there is a head gasket seal failure, due to a variety of reasons. Unfortunately, that's a lot of money to fix on this car.

Good luck with everything.. I mean it.

 

On the old honda, i used to swap out the hg in a couple of hours. lol. Shakey sleeves. Check ur timing.

 

Even if replacing the head gasket were easy, its finding the source of the problem that still remains tricky.